- The new plasma accelerator can generate electron beams with energies up to 7.8 billion electron volts in just 20 centimeters.
- This is almost double the previous record for energy generated by plasma acceleration (set in 2014).
To uncover the mysteries of the universe, it’s important to develop a particle collider that can accelerate electrons and positrons (antimatter counterpart of the electron) to extreme energies.
With current technology, particle accelerators can achieve an energy of 6.5 teraelectronvolts (TeV) per beam. The machines, however, are very big and expensive (32 kilometers long). The aim is to reduce their price and size, without compromising their acceleration capability.
Now, researchers at Berkeley Lab Laser Accelerator (BELLA) Center have built laser plasma accelerators that can generate electron beams with energies up to 7.8 billion electron volts (GeV) in a 20-centimeter-long plasma. This would require 92 meters using traditional accelerators.
In 2014, researchers from the same institute produced electron beams up to 4.25 GeV. This time, they have almost doubled the previous record for energy generated by plasma acceleration.
What Exactly Is Plasma Accelerator?
Plasma accelerator is an advanced machine that uses electric fields associated with electron plasma waves to accelerate charged particles like electron, positrons, and ions.
The plasma acceleration structures are developed either using energetic particle beams or ultra-short laser pulses. These machines could generate plasma waves with electric fields that can be thousands of times stronger than those achieved in traditional accelerators.
Plasma acceleration technique holds great promise for innovation of compact and affordable accelerators for a variety of applications, ranging from high energy physics to industrial and medical applications.
Electron Beam Acceleration To 8 Billion electron Volts
In this study, researchers used a new kind of plasma waveguide that prevents the natural spreading of the laser pulse. They created the plasma channel’s electron density profile (blue) inside a sapphire tube filled with gas (gray).
To control the density, they used a ‘heater’ laser pulse that drills out a small amount of plasma in the middle. The combination of an electrical discharge and an 8-nanosecond long laser pulse (yellow, orange, and red) made the plasma channel strong enough to produce electron beams from 0 to 7.8 billion electron volts over the 20-centimeter accelerator length.
In addition to increasing energy gain, reducing the plasma density can alleviate the dark current. In the next study, researchers will try to precisely control electron injection into the plasma wave to obtain exceptional beam quality. They will also integrate multiple stages (in a row) to achieve even higher energy.